Endocrine Flashcards
1
Q
Carbimazole
A
- Thionamide (antithyroid drug)
- drug of choice
- prodrug; converted to the active metabolite thiamazole via first pass metabolism
- has immunosuppressive properties and thus is useful in the treatment of Graves’ disease
- some serious side effects (agranulocytosis, skin aplasia, rash, nausea, vomiting)
2
Q
propiothiouracil (PTU)
A
- Thionamide (antithyroid drug)
- Less active and shorter half life than carbimazole so twice the dosing is required.
- PTU usually second line.
- reduces the conversion of T4 → T3 peripherally giving some more acute effects.
- better safety data in pregnancy
3
Q
Propanolol
A
- beta blocker
- used for symptomatic treatment in hyperthyroidism
- do not affect hormone levels
4
Q
Potassium Iodide
A
- antithyroid drug
- Reduces thyroid hormone release acutely, used in thyroid storm and pre-operatively
5
Q
levothyroxine
A
- synthetitc T4 used to treat hypothyroidism
- Generally need 1.7-2.0 micrograms / kg / day (with no gland whatsoever)
- Best taken on an empty stomach
- Avoid taking with proton pump inhibitors, ferrous sulphate or calcium
- Start lower, especially in elderly and in cardiac disease
- Increased thyroxine increases the load on the heart
6
Q
Cabergoline
A
- Dopamine agonist (D2 receptor agonist)
- treatment of prolactinoma
- Most commonly used, well tolerated
- Long half-life, therefore only requires once/twice weekly dosing
- Also used to treat parkinson’s (but higher doses)
- Association with cardiac fibrosis
- Echocardiogram at the start of treatment to determine if there is any fibrosis
7
Q
Quinagolide
A
- Dopamine agonist
- treatment of prolactinoma
8
Q
Bromocriptine
A
- Dopamine agonist
- treatment of prolactinoma
9
Q
Thionamides
A
Reduce thyroid hormone synthesis
o Inhibit iodide oxidation
o Inhibit iodination of tyrosine
o Inhibit coupling of iodotyrosines
- T4 has a long half-life (7 days) and therefore treatment with antithyroid drugs can take from 10-20 days for any clinical benefit to be seen.
10
Q
Hydrocortisone
A
- cortisol replacement therapy
- used in adrenal insufficiency
- treatment is initially empirical, as waiting could be fatal
- Metabolised to cortisol. Most physiological way of replacing cortisol
- If unwell, give intravenously first
- Then 15-30mg oral tablets daily in divided doses (for long-term maintenance)
- Try to mimic diurnal rhythm
- Highest levels in the morning, therefore give higher dose in the morning
patient education is important:
- ‘sick day rules’ – double oral hydrocortisone for 3 days when unwell
- Cannot stop suddenly, as this will cause adrenal crisis
- Need to wear identification
11
Q
Fludrocortisone
A
- aldosterone replacement therapy for primary adrenal insufficiency
- not used for secondary insufficiency because aldosterone is regulated by RAAS, not the pituitary
- Careful monitoring of BP and plasma potassium to determine the adequacy of replacement
12
Q
Metyrapone/ketoconazole
A
- Inhibit cortisol production, but not very well
tolerated - Short term measure for treating cortisol excess
13
Q
spironolactone
A
- Competitive antagonist at MR, androgen and progesterone receptors
- Unwanted side effects gynaecomastia, hyperkalaemia
- Management of Primary Aldosteronism
14
Q
eplerenone
A
- Selective MR antagonist, no observed anti-androgen effects
- Management of Primary Aldosteronism
15
Q
amiloride
A
- blocks ENaC, therefore blocks effect of
aldosterone - Management of Primary Aldosteronism
